1 / 7

EE 235 Presentation #1 S. Swisher 3/2/09

Review: “Air-Stable All-Inorganic Nanocrystal Solar Cells Processed From Solution” I. Gur , N. Fromer , M. Geier , A.P. Alivisatos . Science , Oct. 2005. EE 235 Presentation #1 S. Swisher 3/2/09. Motivation: Existing technologies. Inorganic bulk solar cells. Organic solar cells.

merv
Download Presentation

EE 235 Presentation #1 S. Swisher 3/2/09

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Review:“Air-Stable All-Inorganic Nanocrystal Solar Cells Processed From Solution”I. Gur, N. Fromer, M. Geier, A.P. Alivisatos. Science, Oct. 2005 EE 235 Presentation #1 S. Swisher 3/2/09

  2. Motivation: Existing technologies Inorganic bulk solar cells Organic solar cells • Broadband absorption • Superior transport properties • High cost of materials, processing, & installation • Potential cost reduction • Scalable, controlled synthesis • Processed in solution • Low carrier mobility • Limited spectral absorption • Environmental stability problems

  3. Experimental data, Part 1: Bilayer cells • Spin-cast rod shaped CdSe & CdTe NCs • Strong photoconductive effect suggests limited free carriers in dark • Depletion region with built-in field unlikely mechanism for charge separation • Rigid band model more accurate than band bending • Carrier extraction by directed diffusion: electrons and holes both go to lower energy states!

  4. Part 2: Single material & blended cells • Bilayer vs. CdSe or CdTe only, and mixed blends • No rectification in single material no Schottky contact • Blends performed better than single material; implies D-A junction rather than conventional P-N • Bilayer cell = highest efficiency • Very little confinement along length of rod. Free carriers move throughout NC film.

  5. Part 3: Anneal & sinter Best Device: ISC = 13.2mA/cm2 VOC = 0.45V FF = 0.49 Eff = 2.9% • Minimize surface traps by annealing at 400C for 15 minutes • Increase photoconductivity 2 orders of magnitude • No photo-oxidation

  6. Colloidal Semiconductor Nanocrystals, in summary… • Ultra-thin, solution processed, stable in ambient environment • Diffusion-assisted D-A heterojunctions • Sintering enhances performance • Key development toward stable and low-cost solar energy conversion

  7. Questions??

More Related